Helical impeller type liquid ring compressor

ABSTRACT

A helical impeller liquid ring compressor includes a compressor body cooperating with first and second cover plates to define a compression chamber for receiving a helical impeller and a liquid. The compressor body has a compression section. The first cover plate seals a suction end of the compression chamber, and has an air inlet in fluid communication with the compression chamber. The second cover plate seals a pressure end of the compression chamber, and has an air outlet in fluid communication with the compression chamber. The impeller extends through the compression chamber, and includes a shaft rod and at least one helical blade. Upon rotation of the impeller, a liquid ring is generated from the liquid, and cooperates with the shaft rod and the blade to form air chambers.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Taiwanese Application No. 101217839, filed on Sep. 14, 2012.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a liquid ring compressor, and more particularly to a helical impeller type liquid ring compressor.

2. Description of the Related Art

Referring to FIG. 1, a conventional liquid ring compressor 1 includes a compressor body 12 defining a cylindrical compression chamber 11, an impeller 13 disposed eccentrically within the compression chamber 11, a cover plate 14 sealing an end of the compression chamber 11, and intake and exhaust tubes 15, 16 that are connected to the cover plate 14. The compression chamber 11 receives a liquid 17. The cover plate 14 has an air inlet 141 in fluid communication with the compression chamber 11 and the intake tube 15, and an air outlet 142 in fluid communication with the compression chamber 11 and the exhaust tube 16.

When the impeller 13 rotates, a liquid ring is generated from the liquid 17 along an inner surface of the compressor body 12, such that the blades 131 of the impeller 13 cooperate with the liquid ring to form a plurality of air chambers 18 therebetween. Since the air chambers 18 rotate synchronously with the impeller 13, and since the impeller 13 is eccentric with respect to the liquid ring, rotation of the air chambers 18 results in a change in the radial lengths and the volumes of the air chambers 18. When one of the air chambers 18 is communicated fluidly with the intake tube 15 through the air inlet 141, and when its volume is increasing, the gas to be compressed is sucked into the one of the air chambers 18 via the air inlet 141. When one of the air chambers 18 is not in fluid communication with the air inlet 141 and the air outlet 142, and when its volumes is reducing, the gas is compressed in the one of the air chambers 18. The compressed gas can be discharged from one of the air chambers 18 into the exhaust tube 16 via the air outlet 142 when the one of the air chambers 18 is communicated fluidly to the air outlet 142.

During operation of the conventional liquid ring compressor 1, the volumes of the air chambers 18 can be varied by only eccentric rotation of the impeller 13, thereby resulting in a limited compression ratio. Furthermore, since the liquid 17 cannot flow along an axial direction of the compression chamber 11, the space efficiency is reduced.

SUMMARY OF THE INVENTION

The object of this invention is to provide a helical impeller type liquid ring compressor that can increase the compression ratio and the space efficiency.

According to this invention, there is provided a liquid ring compressor comprising:

a compressor body having a compression section;

an upright first cover plate sealing one end of the compression section and having an air inlet adapted to permit a gas to be fed into the compression section therethrough;

an upright second cover plate sealing the other end of the compression section and having an air outlet adapted to permit the gas to flow out of the compression section therethrough, the second cover plate being horizontally spaced apart from the first cover plate along a compressing direction;

a compression chamber defined by the compression section and the first and second cover plates and having a suction end in fluid communication with the air inlet, and a pressure end in fluid communication with the air outlet, the compression chamber being adapted to receive a liquid; and

a helical impeller disposed rotatably within the compression chamber and extending along the compressing direction, the helical impeller including a shaft rod and at least one helical blade disposed on the shaft rod and in the compression chamber;

wherein the helical blade extends from the suction end of the compression chamber to the pressure end of the compression chamber such that, when the helical impeller rotates within the compression chamber, a liquid ring is generated from the liquid by virtue of eccentric force to form a plurality of air chambers among the shaft rod, the helical blade, and liquid ring, and the liquid is driven by the helical blade to flow toward the air outlet along the compression direction, so that the gas is compressed in the air chambers;

wherein each of the air chambers increases gradually in volume, axial length, and radial length when in fluid communication with the air inlet, and reduces gradually in volume, axial length, and radial length when in fluid communication with the air outlet, and a maximum volume of each of the air chambers when in fluid communication with the air inlet being greater than that of each of the air chambers when in fluid communication with the air outlet, so that the gas is compressed, and subsequently is discharged from the pressure end.

As such, due to inclusion of the helical blade in the helical impeller, the axial and radial lengths of the air chambers can be changed, thereby resulting in an increase in a change in the volumes of the air chambers. Hence, the compression ratio and the space efficiency can be increased significantly.

Furthermore, the helical blade can drive the liquid to flow toward the air outlet so as to promote the compressing effect.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of this invention will become apparent in the following detailed description of the preferred embodiments of this invention, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic sectional view of a conventional liquid ring compressor;

FIGS. 2 and 3 are sectional views of the first preferred embodiment of a helical impeller type liquid ring compressor according to this invention;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 2, illustrating that two air chambers are in fluid communication with an air inlet;

FIG. 5 is a sectional view taken along line V-V in FIG. 2, illustrating that one air chamber is in fluid communication with an air outlet;

FIGS. 6 and 7 are sectional views showing a modified compression chamber that is elliptical; and

FIG. 8 is a sectional view of the second preferred embodiment of a helical impeller type liquid ring compressor according to this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described in greater detail in connection with the preferred embodiments, it should be noted that similar elements and structures are designated by like reference numerals throughout the entire disclosure.

Referring to FIGS. 2 and 5, the first preferred embodiment of a helical impeller type liquid ring compressor according to this invention includes a compressor body 2, an upright first cover plate 3, an upright second cover plate 4, a compression chamber 5, and a helical impeller 6. The compressor body 2 has a compression section 21, an intake chamber 22 in fluid communication with the compression chamber 5, an exhaust chamber 23 in fluid communication with the compression chamber 5, an intake tube 24 in fluid communication with the intake chamber 22, and an exhaust tube 25 in fluid communication with the exhaust chamber 23 and the outside. The first cover plate 3 is disposed in the compressor body 2 between the compression chamber 5 and the intake chamber 22 for sealing a suction end 53 (i.e., an end proximate to the intake chamber 22) of the compression chamber 5. An air inlet 31 is formed in the first cover plate 3, and is in fluid communication with the compression chamber 5 and the intake chamber 22, so that a gas can be fed into the compression section 21 therethrough. The second cover plate 4 is disposed in the compressor body 2 between the compression chamber 5 and the exhaust chamber 23 for sealing a pressure end 54 (i.e., an end proximate to the exhaust chamber 23) of the compression chamber 5. An air outlet 41 is formed in the second cover plate 4, and in fluid communication with the compression chamber 5 and the exhaust chamber 23, so that the gas can flow out of the compression section 21 therethrough. The second cover plate 4 is horizontally spaced apart from the first cover plate 3 along a compression direction (I).

The compression chamber 5 is defined by the compression section 21 and the first and second cover plates 3, 4, such that the suction end 53 is in fluid communication with the air inlet 31, and the pressure end 54 is in fluid communication with the air outlet 41. The compression chamber 5 receives a liquid 51. The helical impeller 6 is disposed rotatably and eccentrically within the compression chamber 5, and extends through the compression chamber 5 along the compression direction (I). In this embodiment, the rotating axis of the helical impeller 6 is located above and spaced apart from a central axis of the compression chamber 5 along a horizontal direction such that, when the helical impeller 6 is not rotated, a lower end portion thereof is disposed in the liquid 51. However, according to needs in use, the rotating axis of the helical impeller 6 may be located under the central axis of the compression chamber 5.

The helical impeller 6 includes a shaft rod 61 extending through the compression chamber 5, and a plurality of helical blades 62 disposed on the shaft rod 61 and in the compression chamber 5 and extending from the suction end 53 to the pressure end 54. The compressor body 2 further has two bearings 26 disposed respectively in the suction end 53 and the pressure end 54 of the compression chamber 5.

When the helical impeller 6 rotates within the compression chamber 5, a liquid ring is generated from the liquid 51 along an inner wall surface of the compression section 21 by virtue of eccentric force. The liquid ring is in contact with a portion of said shaft rod 61 and a portion of each of the helical blades 62, such that the helical impeller 6 is eccentric with respect to the liquid ring, so as to form a plurality of air chambers 7 among the shaft rod 61, the helical blades 62, and the liquid ring. The liquid 51 is driven by the helical blades 62 to flow toward the air outlet 41 along the compression direction (I). As such, when the intake tube 24 is connected to a gas source (not shown) to rotate the helical impeller 6, since each of the air chambers 7 is not in fluid communication with an adjacent one of the air chambers 7, the gas in each of the air chambers 7 circulates among a sucked stage, a compressed stage, and a discharged state. At the sucked stage, with particular reference to FIGS. 2 and 4, the air chamber 7 is in fluid communication with only the air inlet 31, and the volume, the axial length 71, and the radial length 72 of the air chamber 7 increase gradually, so that the gas is sucked into the air chamber 7. At the compressed stage, with particular reference to FIGS. 3 and 5, the air chamber 7 is not in fluid communication with the air inlet 31 and the air outlet 41, and the volume, the axial length 71, and the radial length 72 of the air chamber 7 increase gradually, so that the gas in the air chamber 7 is compressed. At the discharged stage, the air chamber 7 is in fluid communication with only the air outlet 41, and the volume of the air chamber 7 reduces gradually, so that the gas is discharged from the air chamber 7 to flow out of the compressor body 2 through the exhaust chamber 23 and the exhaust tube 25. It should be noted that, the maximum volume of each of the air chambers 7 when in fluid communication with the air inlet 31 is greater than that of each of the air chambers 7 when in fluid communication with the air outlet 41, so that the gas is compressed in the compression chamber 5, and subsequently is discharged from the pressure end 54.

Since both the axial length 71 and the radial length 72 of each of the air chambers 7 can be varied when the gas is compressed, the compression ratio can be increased significantly. Furthermore, during rotation of the helical impeller 6, the helical blades 62 drive flow of the liquid 51 along the compression direction (I), so that the liquid 5 can be concentrated toward the air outlet 41. In this manner, the liquid ring formed by the liquid 51 can compress more effectively the gas in the air chambers 7 when the air chambers 7 are located in proximity to the air outlet 41.

If the shape of the compression chamber 5 is changed, the eccentric arrangement of the helical impeller 6 may be unnecessary. For example, with particular reference to FIGS. 6 and 7, when the cross-section of the compression chamber 5 is elliptical, the rotating axis of the helical impeller 6 may be located at the center of the compression chamber 5. In this situation, a plurality of air inlets 31 and a plurality of air outlets 41 may be formed in the first and second cover plates 3, 4.

FIG. 8 show the second preferred embodiment of a helical impeller type liquid ring compressor according to this invention, which is similar to the first preferred embodiment except for the number and pitch of the helical blades 52. Alternatively, the helical impeller 6 may have only one helical blade 62.

To sum up, since the blades 62 are helical, the compression ratio, the space efficiency, and the compressing effect of the liquid ring compressor can be increased.

With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated by the appended claims. 

I claim:
 1. A liquid ring compressor comprising: a compressor body having a compression section; an upright first cover plate sealing one end of said compression section and having an air inlet adapted to permit a gas to be fed into said compression section therethrough; an upright second cover plate sealing the other end of said compression section and having an air outlet adapted to permit the gas to flow out of said compression section therethrough, said second cover plate being horizontally spaced apart from said first cover plate along a compressing direction; a compression chamber defined by said compression section and said first and second cover plates and having a suction end in fluid communication with said air inlet, and a pressure end in fluid communication with said air outlet, said compression chamber being adapted to receive a liquid; and a helical impeller disposed rotatably within said compression chamber and extending along the compressing direction, said helical impeller including a shaft rod and at least one helical blade disposed on said shaft rod and in said compression chamber; wherein said helical blade extends from said suction end of said compression chamber to said pressure end of said compression chamber such that, when said helical impeller rotates within said compression chamber, a liquid ring is generated from the liquid by virtue of eccentric force, and is in contact with a portion of said shaft rod and a portion of said helical blade, so as to form a plurality of air chambers among said shaft rod, said helical blade, and liquid ring, and the liquid is driven by said helical blade to flow toward said air outlet along the compression direction, so that the gas is compressed in the air chambers; wherein each of said air chambers increases gradually in volume, axial length, and radial length when in fluid communication with said air inlet, and reduces gradually in volume, axial length, and radial length when in fluid communication with said air outlet, a maximum volume of each of the air chambers when in fluid communication with said air inlet being greater than that of each of the air chambers when in fluid communication with said air outlet, so that the gas is compressed in said compression chamber, and subsequently is discharged from said pressure end.
 2. The liquid ring compressor as claimed in claim 1, wherein said helical impeller is eccentric with respect to said compression chamber and the liquid ring.
 3. The liquid ring compressor as claimed in claim 2, wherein said helical impeller has a rotating axis that is spaced apart from a central axis of said compression chamber in a horizontal direction.
 4. The liquid ring compressor as claimed in claim 1, wherein said compression chamber has an elliptical cross-section, and said helical impeller has a rotating axis that is located at a center of said compression chamber.
 5. The liquid ring compressor as claimed in claim 1, wherein said helical impeller includes a plurality of said helical blades, each of the air chambers being not in fluid communication with an adjacent one of said air chambers.
 6. The liquid ring compressor as claimed in claim 5, wherein said compressor body further has an intake chamber, an exhaust chamber, an intake tube, and an exhaust tube, said compression chamber being disposed between said intake and exhaust chambers along the compressing direction, said intake chamber being in fluid communication with said compression chamber through said air inlet and with the outside through said intake tube, said exhaust chamber being in fluid communication with said compression chamber through said air outlet and with the outside through said exhaust tube.
 7. The liquid ring compressor as claimed in claim 6, wherein said compressor body further has two bearings disposed respectively in said suction end and said pressure end of said compression chamber, said shaft rod of said helical impeller having two opposite ends extending respectively and rotatably through said bearings. 